Manufacture of aluminous cake



UNITED STATES PATENT OFFICE.

CARL V. PETRAEUS, OF PHILADELPHIA, PENNSYLVANIA.

MANUFACTURE OF ALUMINOUS CAKE.

SPECIFICATION forming part of Letters Patent No. 225,301, dated March 9, 1880.

To all whom it may concern:

Be it known that I, CARL V. PETRAEUS, of the city of Philadelphia, Pennsylvania, have invented an Improvement in the Manufacture of Aluminous (lake from Ferruginous Sulphate of Alumina, of which the following is a specification.

Heretofore the nous aluminous sulphate has been reduced to protoxide of iron by nascent sulphureted hydrogen by a process described in applicants pending application; also. by F. Laurs Letters Patent, N 0. 220,720, October 21, 1879, by using metallic zinc. By Laurs patent the alum will contain more or less oxide of zinc, and sometimes it is desirable not to have this zinc in it.

I have, however, found that metallic lead can be used instead of zinc, and when used the lead is reduced to the state of an extremely fine powder, produced, for instance, by blowing steam into a thin stream of melted piglead, or, still better, when lead is in the spongy state produced by precipitating it from its so lution by a metal, such as zinc, or from sulphate of lead by the action of nascent hydrogen.

The reaction of metallic lead on peroxide of peroxide of iron in ferrugi Application filed December 12, 1879.

not enter the alum except as a trace.

I prefer, after having rendered the aluminous material soluble draw on" the solution of ferruginous sulphate of alumina, and then boil it with-spongy lead until all the ferric oxide is reduced. The amount of lead to be used Varies according to the amount of iron present. Now the precipitate is allowed to settle and the clear solution drawn off and evaporated, as usual, to 45 50 Baum, and then run into cakes.

WhatI claim as new is The herein-described process for manufacturing white aluminous cake by reducing the peroxide of iron in ferrugiuous sulphate of alumina by adding metallic lead in the state of a fine powder or in a spongy condition, and then boiling or otherwise agitating the solution;

In testimony of which invention ll hereunto set my hand.

. CARL V. PETRAEUS. Witnesses:

GORDON SEcKnL, FRANK WILLING LEACH.

by sulphuric acid, to 

